Over the years, bodily characteristics have been determined by obtaining a sample of bodily fluid. For example, diabetics often test for blood glucose levels with a blood glucose meter. Traditional blood glucose determinations have utilized a painful finger stick using a lancet to withdraw a small blood sample that is used by the blood glucose meter. This results in discomfort from the lancet as it contacts nerves in the subcutaneous tissue. To obtain a measure of control or information on a diabetic's condition, several finger sticks and tests are required each day (8 or more such tests a day are not uncommon). The pain of lancing and the cumulative discomfort from multiple needle sticks is a strong reason why patients fail to comply with a medical testing regimen used to determine a change in characteristic over a period of time. In addition, these blood glucose meters are only designed to provide data at discrete points, and even with multiple tests a day, do not provide continuous data to show the variations in the characteristic between testing times.
A variety of implantable electrochemical sensors for use with monitors have been developed for detecting and/or quantifying specific agents or compositions in a patient's blood. For instance, glucose sensors have been developed for use in obtaining an indication of blood glucose levels in a diabetic patient. Such readings are useful in monitoring and/or adjusting a treatment regimen which typically includes the regular administration of insulin to the patient. Thus, blood glucose readings from the monitor improve medical therapies with semi-automated medication infusion pumps of the external type, as generally described in U.S. Pat. Nos. 4,562,751; 4,678,408; and 4,685,903; or automated implantable medication infusion pumps, as generally described in U.S. Pat. No. 4,573,994, which are herein incorporated by reference. Typical thin film sensors are described in commonly assigned U.S. Pat. Nos. 5,390,671; 5,391,250; 5,482,473; and 5,586,553 which are incorporated by reference herein. See also U.S. Pat. No. 5,299,571. However, the monitors and electrochemical sensors often require calibration using readings obtained from blood glucose meters to augment and adjust for drift over time. Thus, although the monitors and electrochemical sensors provide more accurate trend information, a separate blood glucose meter is still often required.
A user must often carry multiple devices to test different aspects of the same value or characteristic. For instance, the a user would need a blood glucose meter and blood glucose monitor. In addition, individuals are also carrying other electronic devices, such as an infusion device, cellular telephones, personal entertainment systems (such as radios, cassette players, CD players, or the like). They may also include small personal computers, personal data assistants (PDAs) or the like. Thus, users often carry a large number of separate electronic devices, which can be cumbersome and inconvenient to handle.